Crimping method and apparatus



ct. 7, 1958 L, W, RAINARD 2,854,701

CRIMPING METHOD AND APPARATUS Filed March '7,- 1956 United States Patent O CRllVIPING METHD AND APPARATUS Leo W. Ranard, Wilmington, Del., assigner to Joseph Bancroft & Sons Co., Wilmington, Del., a corporation of Delaware Application March 7, 1956, Serial No. 570,145

8 Claims. (Cl. 1966) This invention relates to a method and apparatus for producing a permanent artificial crimp in textile fibers.

The invention is applicable to cellulosic textile fibers and provides a novel and improved means for producing in such fibers a permanent crimp of the saw tooth type in which the fibers are formed into a series of angular bends separated by straight fiber lengths or legs. Such a crimp `may be produced in a stuffer crimper wherein the fibers to be crimped are fed between feed rolls into `a closed lcrimping chamber against a mass of crimped fibers held compacted in said chamber so that the fibers are folded over into a zig-zag crimp as they leave the bite of the feed rolls. The crimped fibers are continuously advanced to the discharge end of said chamber at a predetermined rate dependent upon the length of time the fibers are to remain in the chamber and during which time the setting operation of the present invention takes place.

The fibers or yarns may be in the form of a rope or sliver composed of carded staple fibers or may be in the form of a bundle of continuous filaments which may or may not be twisted into yarn. The invention is applicable for example to regenerated cellulose rayon, cotton, linen, hamp, ramie, jute, and the like.

In accordance with this invention the fibers are impregnated with an impregnant capable of fixing the crimped eect upon heating the. impregnated fiber. Such impregnant may be any one of a wide variety of materials, either a thermosetting resin precondensate such as dimethylol melamine or an impregnant adapted to react with the liber itself upon heating in the curing zone, such as dimethylol ethylene urea. Usually, such impregnation is effected by application of an aqueous solution of the resin materials, followed by drying the fibers to provide a moist condition.

The nature of the impregnant employed may be varied without departing from the scope of the invention, the important consideration being that the impregnant be capable of fixing the crimp upon heating the impregnated crimped fibers so that the set is not affected by subsequent washing or steaming or by other conditions normally encountered in the use or fabrication of the fibers.

The fibers are impregnated while in the crimping chamber or prior to being fed to the crimping chamber and the impregnant is cured while the fibers are held compacted in the crimping chamber, at least to a point such that the crimp is retained when the compacting force is released. The complete curing may be effected in the crimping chamber or in a separate curing zone.

The invention will be better understood by referring to the following description, taken in connection with the accompanying drawing in which a specific embodiment has been set forth for purposes of illustration.

In the drawing:

Fig. 1 is a diagrammatic view of an apparatus embody- `ing the invention with parts shown in section; and

' i l2,854,701 ICC Patented Oct. 7, 1958 Fig. 2 is a section on a larger-scale taken on the line 2-2 of Fig. 1.

Referring to the drawing more in detail the filament tow or yarn 10 is passed through feed rolls 11 into an impregnation solution 121 in. a tank 13. The impregnated yarn is removed from the solution 12i through squeeze rolls 14 which. remove the excess solution and; i'sr fed through a drier 15 and aroundg'uide rolls 16 to a guide'. 17 which directs the impregnated and dried: yarn into the stuffer crimper.

The stulfer crimper is shown` as comprising heater blocks 20, 21 and 22 mounted on a supporting plate 24 and formed with cylindrical bores in which sleeves 25, 26 and 27 respectively are. secured..

The plate 24 carries a bearing in which is journaled a shaft 28. carrying a feed roll 29. A second feed roll 30 is carried by a shaft 31 journaled in a bearing. in an arm 32 which is` pivotally attached by a pin 33 to a bracket 34 which is attached to or carried by the plate 24. The shaft 28 is driven by a source of4 power such as a. motor not shown. They shaft 31 is driven in, unison therewith by meshing gears 35 and 36 carried by the respective shafts 28 and 31.

The feed rolls 29 and 30 are held in pressure engagement with the yarn 10 bylmeans of a spring 37 attached at one end to a post 38 on the arm 32 and at the other end to a post 39 on the plate 24. Adjustment is` provided by a threaded pin 40 and. nut 41.

The yarn 10 is guided to the 'bite ofv the feed rolls- 2h and 30 by the guide 17 which is attached by a screw 42 to the plate 24. The lower end of sleeve 25,

' is slotted to receive the rolls 29 and 30 and extends below:v

the bite of the rolls to form therewith a substantially closed crimping chamber into which theA yarn 10y is fed for crimping.

The blocks 20, 21 and 22 may be heated by suitable means such as by Calrod units 45, 46 and 47 respectively which areV vinserted in bores in blocks 20, 21 and 22 and. extend parallel to the sleeves 25, 26 and 27 so as to. heat the walls of the sleeves. The Calrods may be con.- trelled so as to heat the yarn4 in the sleeves to the; temperature necessary for curing the impregnant above. described.

The sleeves 25, 26v and 27 are joined by collars 50. and 51 which may be threaded for ease of assembly. The collars 50 and 5I are formed with ports 52 and 53- communicating. with pipes 54 and55 respectively through which fluid can be introduced. The rate of flow of such. liud can be regulated by metering valves 56 and 57 respectively. t

The sleeve 25 below the heater block 20 is provided with a plurality of inletv ports 60 which are disposed radially around the periphery thereof and communicate with an eccentric annular groove 61 in the outer peripheryv of the sleeve 25. A coupling ring 62 is clampedv around, the sleeve 2S in alignment with the annular groove 61 by a clamping screw 63 and carries a pipe 64 having a metering valve 65 by which a fluid may be introduced through the ports 60 into the interior of the sleeve 25.

A plug 68 is inserted in the top of the sleeve 27 to` rest upon the crimped yarn 69 within the sleeve. The plug 68 may be provided with a bore 70 through which the crimped yarn 69 is withdrawn by take-up rolls 71 which may be operated at a constant rate bearing a predetermined relationship to the rate of feed of the yarn 10 by the feed rolls 29 and 30, which relationship may be adjusted in response to variations in the portion of the plug 68, so as to maintain the plug at a constant level within the sleeve 27.

From the take-up rolls 71 the crimped yarn 69 may be fed to an oven 73 which is maintained at a temperature adapted for the nal curing of the impregnant. The

3 crimp set yarn may be removed from the oven 73 by take-up rolls 74 and fed to a winding device not shown.

To permit the escape of steam or vapor during the heating of the fibers the sleeves 25, 26 and 27 are provided within the blocks 20, 21 and 22 with a plurality of sets of radial exhaust ports 76, 77 and 78 respectively which are disposed around the periphery of the sleeves and register with exhaust passages 79, 80 and 81 respectively in the blocks 20, 21 and 22.

In the operation of this process the tow or yarn to be crimped is lrst treated With `the impregnant solution 12 in the tank 13 and is dried to a moist state by'the drier 15. The impregnated and dried tow or yarn is then fed by feed rolls 29 and 30 into the crimping chamber formed by the sleeve 25 against the pressure exerted by the mass t of crimped yarn in the chamber. A suitable catalyst may be introduced into the mass of bers through the pipe 64 or the pipe 54 or through both pipes as required.

If the catalyst is introduced through the lower pipe 64 the lbers are cured in the sleeves 25, 26 and 27. If the catalyst is introduced through the pipe 54 the fibers dried in the sleeve 25 are cured in the sleeves 26 and 27.

As the bers advance through the sleeves 25, 26 and 27 they are heated to a predetermined temperature suited for curing or partially curing the impregnant. The time that Vthe bers are exposed to the curing temperature is dependent upon the rate of feed by the feed rolls 29 and 30 and upon the length of the heated portion of the sleeves.

The pretreatment in the tank 13 and drier 15 may be omitted if sucient dwell is provided in the crimper itself in which case the fibers are fed directly to the feed rolls 29 and 30, the impregnant is introduced through the pipe 64, dried in the sleeve 25, the catalyst introduced through pipes 54 and the impregnant cured in the sleeves 26 and 27. If further drying is required between the impregnation and the introduction of the catalyst the impregnant may be introduced through the pipe 64, the fibers dried in the sleeves 25 and 26, the catalyst introduced through the pipe 55 and cured in the sleeve 27.

In a further embodiment the impregnant and catalyst may be introduced together, either in the tank 13 or through the pipe 64. The order of introduction may also be reversed, the catalyst being introduced rst and the impregnant at a later stage followed by curing in the crimper.

It is possible to impregnate the fibers in tank 13 with one of the chemicals used in making the precondensate, for example urea, and then to introduce the others, for example formaldehyde, through pipe 64. The catalyst may be added to either ingredient or introduced separately through pipe 54 or 55.

If the curing is complete in the sleeves 25 and 26 the block 22 may be cooled instead of heated so as to cool the fibers to a temperature to stop the reaction before the yarn is wound onto a package.

In some cases a softening or lubricating agent may be introduced through the upper pipe 55 followed by drying in the sleeve 27.

The upper portion` of the sleeve 27 which extends above the block 22 constitutes a cooling zone in which the bers are cooled before being removed from the crimper. In the event that the curing is not complete in the sleeve 27 and further curing is to be effected in the oven 73, the intermediate cooling zone in the upper portion of the sleeve 27 may be eliminated by making the sleeve terminate as closely as possible at the top of the heated block 22. If nal curing takes place in the oven 73 additional impregnant material may be introduced through the upper pipe 55.

Following are various examples of the sequence of steps which may be used in carrying out this invention:

(l) The yarns may be impregnated, squeezed, partially dried before entering the crimping chamber, then crimped and cured in the crimping chamber.

(2) The yarns may be impregnated and squeezed before entering the crimping chamber, then crimped, dried and cured in the crimping chamber.

(3) The yarns may be impregnated and partially dried before entering the crimping chamber, then crimped and the catalyst introduced through lower inlet pipe 64 or intermediate inlet pipe 54.

(4) The catalyst may be introduced in the tank 13 or through the lower pipe 64, directly in sleeve 25, the impregnant introduced through pipe 54 or v55 and cured in the crimping chamber.

(5) The yarns may be crimped and the impregnant be injected through pipe 64 or 54, dried and cured in the crimping chamber.

(6) The yarn may be crimped, the impregnant injected through pipe 55, partially cured in sleeve 27 and finally cured in oven 73.

(7) The yarn may be crimped and the impregnant injected through pipe 64, dried, the catalyst injected through pipe 54 or'55, dried and cured in the sleeve 27, or partially cured in sleeve 27, and finally cured in oven 73.

(8) The yarn may be crimped, the catalyst injected through pipe 64, dried, the impregnant injected through pipe 54 or 55, and dried and cured in the sleeve 27.

(9) In any of the above combinations a softening agent or a lubricant may be introduced through the pipe 54 or 5S or into the top of the sleeve 27 Types of amino-plast resin impregnants which can be used are as follows: Urea formaldehyde types having formaldehyde urea mol ratios from 1:1 to 2:1, such as sesquimethylol urea; modified 'urea formaldehyde, such as dimethylol ethylene urea, dimethylol 1,2 propylene urea, dimethylol 1,2 butylene urea, dimethylol 3,4 butylene urea; methylol melamine resins, such as mixtures of dimethylol and trimethylol melamines or mixtures of tetramethylol and pentamethylol melamines; methylatedmethylol melamines, such as dimethyl trimethylol melamines.

The following examples are based on pickups of the fibers:

Example I:

20 lbs. dimethylol urea 32 lbs. methylated methylol melamine 20 lbs. cationic softener 20 lbs. catalyst Add water to make 100 gallons.

Example Il:

45 lbs. dimethylol urea 20 lbs. cationic softener '20 lbs. catalyst Add water to make 10G gallons.

Example III:

60 lbs. methylated methylol melamine 20 lbs. cationic softener 20 lbs. catalyst Add water to make 100 gallons.

Example IV:

40 lbs. methylated methylol melamine 25 lbs. dimethylol urea l5 lbs. cationic softener 2O lbs. catalyst 4 lbs. polyvinyl alcohol (99% hydrolyzed) Add water to make 100 gallons.

Example V:

15 lbs. methylated methylol melamine 24 lbs. dimethylol urea 20 lbs. cationic softener 16 lbs. catalyst 2 lbs. polyvinyl alcohol (99% hydrolyzed) Add water to make 100 gallons.

Example 40 lbs. methylated methylol melamin 20 lbs. cationic softener 18 lbs. catalyst Y 2 lbs. polyvinyl alcohol (99% hydrolyzed) Add water to make 100 gallons.

Example VII:

56 lbs. methylated methylol melamine 20 lbs. cationic softener 22 lbs. catalyst 2 lbs. polyvinyl alcohol (99% hydrolyzed) Add water to make 100 gallons.

Example VIII:

30 lbs. sesquimethylol urea 30 lbs. dimethylol ethylene urea 20 lbs. cationic softener 20 lbs. catalyst Add water to make 100 gallons.

Example IX:

60 lbs. methylated methylol melamine 20 lbs. cationic softener 20 lbs. catalyst 100 lbs. water A suitable cationic softener is s-Di 1-(2 stearamidoethyl) urea mono acetate. However, other cationic softeners, such as dimethyl ammonium methyl sulfate of monostearylmetaphenylene diamine would be satisfactory.

The catalyst generally used is a 70% solution of magnesium chloride hcxahydrate. However, several other catalysts, such as methylhydroxypropanolamine hydrochloride may be satisfactorily used. Certain types of catalysts could even be utilized in the gaseous state, such as hydrogen chloride which inthe presence of water would be acidic. The invention is not to be limited as to catalyst .since any of the catalysts commonly used with thermosetting resins may be used.

The composition of Example II is preferred for regenerated cellulose rayon. The remaining examples are satisfactory for the other cellulosics.

In processes in which the catalyst is to be introduced Iseparately it would be removed from the formulation, and a more concentrated solution would be injected into the inlet orifices. For example, the formula of Example l may be separated into (a) an impregnant consisting of:

20 lbs. methylated methylol melamine 32 lbs. dimethylol urea 20 lbs. cationic softener Add water to make 100 gallons.

and (b) 2l lbs. of catalyst dissolved in 21 lbs. of water which is separately injected at a rate to inject 5 grams of catalyst while 100 grams of yarn are passing the: injection port in a given length of time.

The impregnant may be injected at a rate so that 100 grams would be injected during the time that 100 grams of yarn are passing the port. The concentration of the ingredients in the impregnant may be increased and the rate of injection decreased if so desired.

Cotton yarn or rayon may be impregnated with any of the above mixtures, squeezed to leave about a 100% increase in weight, partially dried to a to 15% moisture content and crimped in a stuifer crimper. The crimped fiber is maintained in the crimping chamber at a. temperature above 290 F. for a period of about 21/2 minutes. The time and temperature may be varied in versely. For example the fibers may be held in the crimping chamber forv from live minutes to a half of a minute at temperatures varying from 200 F. to 450 F. The shorter time being coupled wit-h the higher temperatures and vice versa. Under the above conditions the resin is completely cured before the fibers leaver the crimping chamber and produces a permanently set crimp which is resistant to washing and boiling.

What is claimed is:

l. The method of imparting a permanently set crimp to cellulosic textile bers, which comprises feeding said fibers continuously in the form of a tow or yarn into a closed crimping zone against a mass of crimped fibers held compacted in said zone to cause the fibers to fold and form zig-zag crimps as they contact said mass of crimp fibers, advancing the crimped fibers along said zone to a discharge point, applying to the fibers at a point in advance of their discharge point a resinous impregnant capable of setting the crimp in said fibers under the action of heat, applying heat to said crimped fibers, as said crimped fibers pass through said zone, at a plurality of sequential heating areas and feeding a catalyst for said resinous material into said zone in advance of at least one of said heating areas, whereby permanent setting of the crimp in said fibers is effected prior to the removal of said crimp fibers from said discharge point.

2. The method set forth in claim 1 in which the fibers are treated with said impregnant beforel being fed into said crimping zone.

3. The method set forth in claim 1 in which the fibers are treated with said impregnant and at least partially dried before being fed into said crimping zone.

4. The method set forth in claim l in which the impregnant is introduced into said crimping zone.

5. The method set forth in claim l in which the crimped fibers are fed from said crimping zone into an oven for the final curing of -said impregnant.

6. Crimping apparatus comprising a tube forming a crimping chamber, a pair of feed rolls disposed to feed fibers for crimping into one end of said tube, a closure member disposed to control the discharge of crimped fibers from the other end of said tube, heating means to heat said tube for a portion of its length to provide a heating zone for the fibers within said tube, said tube having an inlet port for a treating fluid in advance of said heating zone, an exhaust port in said heating zone, and a second inlet port disposed beyond said exhaust ports in said heating zone, and a third inlet port beyond said second inlet port in the direction of travel of said fibers in said tube.

7. Crimping apparatus compri-sing a tube forming a crimping chamber, a pair of feed rolls disposed to feed fibers for crimping into one end of said tube, a closure member disposed to control the discharge of crimped fibers from the other end lof said tube, heating means to heat said tube for a portion of its length to provide a heating zone for the fibers within said tube, said tube having an inlet port for a treating uid in advance of said heating zone, a plurality of exhaust ports disposed along said heating zone, and a second inlet port disposed beyond said exhaust ports in said heating zone.

8. Crimping apparatus comprising a tube forming a crimping chamber, a pair of feed rolls disposed to feed fibers for crimping into lone end of said tube, a closure member disposed to control the discharge of crimped fibers from the other end of said tube, heating means to heat said tube for a portion of its length to provide a heating zone for the fibers within said tube, said tube having an inlet port for a treating uid in advance of said heating zone, a plurality of exhaust ports disposed along said heating zone, and a second inlet port disposed beyond said exhaust ports in said heating zone, and a third inlet port beyond said second inlet port in the direction of travel of said fibers in said tube.

(References on following page) 3,855,701 7 Refgreges Cited nftherle of this `patent 2,575,781 .A `,1111151115113 .sTATEs BATENIS 22,363,019v vSchurmm-gn?et al Nov. 21,1944 2,733,122

2,556,011 Swayze et a1 June 5, 1951 i 2,734,228

-.8 Barach Nov. 20, 19,51 Hemmi Dec. 30, '1952 Kqen Y Feb. 16, 1954 Herele et al Jain, l'31, 1956 Hay Feb. V14, 1956 

